Complex regional pain syndrome (CRPS) is a chronic neuropathic pain disorder. Pain catastrophizing, characterized by magnification, rumination, and helplessness, increases perceived pain intensity and mental distress in CRPS patients. As functional connectivity patterns in CRPS remain largely unknown, we aimed to investigate functional connectivity alterations in CRPS patients and their association with pain catastrophizing using a whole-brain analysis approach. Twenty-one patients with CRPS and 49 healthy controls were included in the study for clinical assessment and resting-state functional magnetic resonance imaging. Between-group differences in whole-brain functional connectivity were examined through a Network-based Statistics analysis. Associations between altered functional connectivity and the extent of pain catastrophizing were also assessed in CRPS patients. Relative to healthy controls, CRPS patients showed higher levels of functional connectivity in the bilateral somatosensory subnetworks (components 1~2), but lower functional connectivity within the prefronto-posterior cingulate (component 3), prefrontal (component 4), prefronto-parietal (component 5), and thalamo-anterior cingulate (component 6) subnetworks (p<0.05, family-wise error corrected). Higher levels of functional connectivity in components 1~2 (β=0.45, p=0.04) and lower levels of functional connectivity in components 3~6 (β=-0.49, p=0.047) were significantly correlated with higher levels of pain catastrophizing in CRPS patients. Higher functional connectivity in the somatosensory subnetworks implicating exaggerated pain perception and lower functional connectivity in the prefronto-parieto-cingulo-thalamic subnetworks indicating impaired cognitive-affective pain processing may underlie pain catastrophizing in CRPS.
Bibliographical noteFunding Information:
This research was supported by the National Research Foundation of Korea funded by the Korean government (NRF-2020M3E5D9080555 and NRF-2020R1A6A1A03043528 to I.K.L. and NRF-2020R1A2C2005901 to S.Y.).
© Experimental Neurobiology 2023.
- Complex regional pain syndrome
- Functional magnetic resonance imaging
- Pain catastrophizing